Which statement correctly describes Class A airspace's vertical limits?

Which statement correctly describes Class A airspace's vertical limits?

• A. 0 to 60,000 ft MSL
• B. 18,000 to 60,000 ft MSL
• C. Surface to 60,000 ft MSL
• D. 50,000 to 60,000 ft MSL

Answer: (B)

Class A airspace in the United States starts at 18,000 feet MSL and extends up to 60,000 feet MSL. This vertical range keeps all IFR traffic in a single, highly controlled environment from en route to high altitude, and it requires IFR clearance and two-way communication for entry. The lower limit isn’t at the surface, and the upper limit isn’t 50,000 feet or 60,000 feet only; the correct span begins at 18,000 and goes up to 60,000, which is why that option fits.

Class A airspace in the United States starts at 18,000 feet MSL and extends up to 60,000 feet MSL. This vertical range keeps all IFR traffic in a single, highly controlled environment from en route to high altitude, and it requires IFR clearance and two-way communication for entry. The lower limit isn’t at the surface, and the upper limit isn’t 50,000 feet or 60,000 feet only; the correct span begins at 18,000 and goes up to 60,000, which is why that option fits.